A torque fluctuation absorber, for Example, is located in the power transmission path between an engine and a transmission and absorbs (suppresses) fluctuating torque that occurs due to the engine and the transmission. There are torque fluctuation absorbers that comprise a damper unit that absorbs fluctuating torque through spring force, a hysteresis unit that absorbs (suppresses) fluctuating torque through hysteresis torque due to friction or the like, and a limiter unit that causes slipping to occur when torsion of a rotating shaft cannot be absorbed by a damper unit or hysteresis unit. In addition, in order that a coil spring is not crushed due to relative rotation between side plates and hub, the damper unit has stopper construction that allows relative rotation between the side plates and hub within a predetermined range, but prevents relative rotation outside that range.
For Example, in Patent Document 1, a torque fluctuation absorber is disclosed that has a stopper construction between two inner convex sections that are formed around the end section on the inside of a disk to which the side plates are attached by rivets, and that allows relative rotation between the side plates and a hub within the movable range in the circumferential direction of an outer convex section that is formed around the end section on the outside of the flange section of the hub, and prevents relative rotation between the side plates and hub by locking the outer convex section by the inner convex sections.
[Patent Document 1]
JP-2005-127507A
The disclosure of above Patent Document is incorporated by reference thereto. The following analysis is given by this disclosure.
However, in the conventional torque fluctuation absorber disclosed by JP-2005-127507A, a disk to which friction material is fastened is held between two side plates fastened inside the limiter unit using rivets, so the overall size of the device in the axial direction becomes large, and there was limitation in the space in the axial direction.
Thus, there is much to be desired in the art. In one aspect, there is a need to provide a torque fluctuation absorber having a stopper construction that can improve the effective use of space in the axial direction.